Improvement in devices for converting motion



M. CROSSMAN.

DEVICE FOR CONVERTING MOTION.

No.170,427, Patented Nov. 23,1875.

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UNITED STATES PATENT OEEroE.

MONTGOMERY OROSSMAN, OF MARSHALL, MICHIGAN, ASSIGNOR OF ONE- HALF HIS RIGHT TO PRATT A. SPIGER, OF SAME PLACE.

IMPRQVEMENT IN DEVICES FO R CONVERTING MOTION.

Specification forming part of Letters Patent No. 170,427. dated November 23, 1875 application filed October 25, 1875.

To all whom itmay concern:

Be it known that I, MONTGOMERY Cnoss- MAN, of the city of Marshall, State of Michigan, have invented a new and useful Device for Oonvertin g Motion, of which the following is a full and accurate description, reference being had to the accompanying drawing, which shows a single elevation of the device, which we deem snfficient to illustrate its construction.

A face-plate and wrist-pin are formed upon a shaft, F, or a crank in the middle of a shaft may be used. A Y- shaped lever, A, having its fulcrum at 1, has one branch, e,-connected with the wrist-pin3 by a simple link, B. The other branch, 6, is hinged at 4 to the pitman D. As the shaft F revolves, the point 4 moves in a more or less near approximation to a straight line as the point 1 is at a greater or less proportionate distance from the center of the shaft. By making both the lever A and the link B short in proportion to the stroke of the pitman, the downstroke of the pitman is made much quicker than the upstroke, the motion of the shaft being uniform, and in the direction indicated by the arrow a The philosophy of this difl'erence of motion will be understood is 1b. Now, this lb is less than let. Hence,

while the wrist-pin is on that side of the shaft toward 1, the motion of the lever A is more rapid than when the wrist-pin is on the opposite side. A further consideration of the case would show that the upstroke requires more than half a revolution, while the downstrnke requires as much less than half a revolution. This arrangement, with suitable modifications of proportions, may be adapted to many special uses. An instance of special fitness is its application to the transmission of motion from the main shaft of a windmill to its pitman for operating a pump. Here, the slow and powerful upstroke raises a column of water without sudden and undue strain, while the quicker downstroke meets little resistance. Another important advantage of its use in a windmill arises from the small lateral motion of the pitman. This permits the use of a much smaller tubular pivot, and consequently secures a much more prompt obedience of the mill to the regulator, or to the shifting direction of the wind.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is

The device for converting motion herein described, consisting of the link B and Y- shaped leverA, in combination with a rey'olving crank or wrist pin, 3, and pitman-rod D, when arranged substantially as shown and described.

MONTGOMERY GRO SSMAN. 

